Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 28 2 2026 03 01 Effects of Starvation, Dietary Regimes, and Temperature Stress on Hemocyte Profiles and Phenoloxidase Activity in Larvae of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) 367 383 16876 EN Jamaneh Karimian Department of Plant Protection, Faculty of Agriculture, Shahrood University of Technology, Shahrood, Islamic Republic of Iran. Maryam Ajamhassani Department of Plant Protection, Faculty of Agriculture, Shahrood University of Technology, Shahrood, Islamic Republic of Iran. Journal Article 1970 01 01 <em>T</em>. <em>absoluta</em>-infected tomato fruits were collected from fields and larvae were extracted<span dir="RTL"> </span>from fruits after two generations of rearing. Hemolymph was extracted with a capillary tube and placed on a slide.<span dir="RTL"> </span>Hemocytes were identified through Giemsa staining and observed under light microscopy at 40× magnification. Starvation stress was induced for 12 and 24 hours while the control group remained unstressed. Hemocyte counts were determined using a hemocytometer under light microscopy at 40× magnification. Starved larvae exhibited significantly reduced total hemocyte counts, plasmatocytes, and granulocytes compared to the control group. Larvae reared on eight tomato varieties (Superchef, Basimo, Hartiva, Berantta, Breivio, Gs15, 1012, and 8320) displayed variable hemocyte densities, with the highest counts observed in those fed on Superchef and Gs15 cultivars. For thermal stress experiments, third- and fourth-instar larvae were exposed to 28 and 4°C for 12 and 24 hours. Control groups for the third and fourth instar larvae were maintained at 25±1°C. In total, hemocyte and granulocyte densities were significantly reduced across all thermal treatments compared to the controls. Plasmatocyte counts in the third-instar larvae subjected to 12 hours of heat stress (327.5±18 cell mm³ hemolymph) and cold stress (320±34.3 cell mm³) were higher than those in the control (294.3±23.3 cell mm³). Phenoloxidase activity exhibited a direct correlation with hemocyte alterations across all experimental conditions. This study provides a foundation for further investigations into the pest's physiological defense mechanisms. <br><br> https://jast.modares.ac.ir/article_16876_b294fccdfe95bc7f7dd813216a821a76.pdf